A new procedure for the preparation of thick polymethacrylate films bonded in 25 μm i.d. fused-silica capillaries is developed. The etched silica surface is first modified with an unsaturated organosilane, which is later incorporated into the polymer film. The capillary is then filled with a monomer solution, and polymerization is initiated by incubation at elevated temperature. This thermoinit...

Preservatives are chemical substances whose role is to protect medicinal products against harmful changes caused by microorganisms. They are added to sterile medicinal products, such as eye drops and multidose solutions for injections, as well as to non-sterile products, such as water oral solutions, creams, gels, suppositories and capsules with liquid content. The most commonly used preservati...

In the last few years increasing evidence has been presented that acylated flavonoids are widespread in higher plants [1—3], Besides the well known phenolic acids (hydroxybenzoates, hydroxycinnamates), aliphatic acids have only recently been extensively detected as acyl moieties of anthocyanins or gly­ cosides of (iso)flavones and flavonols. To date, ace­ tic, butyric, malonic, 2-methylbutyric,...

The relative position of the hydroxylic and the carboxylic group in the isomeric hydroxybenzoate (HB) anions is known to have a large impact on transport properties of this species. It also influences crucially the self-organisation of cationic surfactants. In this article a systematic investigation of aqueous solutions of the ortho, meta, and para isomers of the HB anion is presented. Molecula...

Pseudomonas sp. WR912 was isolated by continuous enrichment in three steps with 3-chloro-, 4-chloro-, and finally 3,5-dichlorobenzoate as sole source of carbon and energy. The doubling times of the pure culture with these growth substrates were 2.6, 3.3, and 5.2 h, respectively. Stoichiometric amounts of chloride were eliminated during growth. Oxygen uptake rates with chlorinated benzoates reve...

p-Hydroxybenzoate hydroxylase (PHBH) is a homodimeric enzyme in which each subunit noncovalently binds one molecule of FAD in the active site. PHBH is a model system for how flavoenzymes regulate reactions with oxygen. We report single-molecule fluorescence studies of PHBH in the absence of substrate that provide data consistent with the hypothesis that a critical step in substrate binding is t...

J Econ Entomol 82(6): 1825-1829 (1989) ABSTRACT Oriental fruit moth, Ctapholita molesta (Busck), was reared on modifications of a previously developed small lima bean diet Initial experiments showed that different types of beans substituted for lima beans produced similar yields of oriental fruit moth pupae Fresh, thinning apples provided the best diet for high yields and high pupal weights, bu...

Several fluorinated derivatives of p-hydroxybenzoate were synthesized and examined as substrates in the reaction catalyzed by p-hydroxybenzoate hydroxylase. All the derivatives tested served as substrates, undergoing tightly coupled hydroxylation by molecular oxygen. Hydroxylation of the difluoro and tetrafluoro derivatives liberated stoichiometric amounts of fluoride. Little or no fluoride was...